We know little about influenza pandemics in the pre-1918 era. Historians and medical writers have understandably been fascinated by the 1918-19 disaster and almost all accounts of earlier outbreaks are sketches based on a handful of old compiled works. This proposal is for a detailed historical study of earlier pandemics based on primary sources and on modern understanding of the disease. The development of medical knowledge and influenza's place in the miasmatist-contagionist dispute will be explored and the historical roots of modern ideas on the origins and epidemiology of the disease will be explored. Mortality, morbidity, and diffusion patterns of past epidemics will be analyzed and compared to the behavior of twentieth-century viral strains, and historical data on seasonality, climate, herald waves, and animal associations will be discussed.